The inventive concept relates to a flash memory device and a memory system including the same, and more particularly, to a flash memory device and a memory system including the same by which operating circumstances are optimized according to temperatures.
Continuing efforts to improve the performance of flash memory devices have resulted in increases in both the integration density of memory cells and the number of bits stored in each of the memory cells. This has resulted in a reduction in read margins, increasing the likelihood of read errors. Various techniques have been attempted to minimize or prevent read failures. For example, a read failure may be avoided by controlling a pass voltage level or read voltage level during a read operation.
In the meantime, a threshold voltage of a flash memory cell tends to vary with a variation in temperature. This variation of threshold voltage can further reduce read margins, and can alter conditions upon which preventative measures to avoid read failures have been premised. As a result, the operating reliability of the flash memory devices may deteriorate with temperature variations.